Surprisingly enough I agree with Colin.
But I also agree with Bob.
When I think flip-flop, I immediately think SR (like the one in a 555), JK, or D? (and yeah, I know there's more. Pretty much by definition these are inherently bistable. Note that the 4047 is described as a multivibrator rather than a flip-flop.
Monostable, bistable, and astable refer to a circuit with 2 states (although, why not 3 or more?) and describes the operation when in one state or the other.
There's a lot of overlap between the two, and I feel the terms are often used rather too loosely. I wouldn't doubt someone will demonstrate this by finding a 4047 datasheet with the word(s) "flip-flop" in the description of the device.
It's probably a bit "pot-ay-toe, pot-ah-toe", and no matter what I prefer, people are always going to get it wrong about 50% of the time
.
My first thought when reading the original question was "you don't have to. Look at the block diagram of the 555 because there's an SR flip flop in there."